In the year 1590...
- The War of the Three Henrys continues in France. French king Henry IV again defeats the forces of the Catholic League at the Battle of Ivry, but his third attempt to capture Paris fails when the League defenders are reinforced by a Spanish army under Alessandro Farnese.
- In the successful Siege of Odawara Castle, Japanese hegemon Toyotomi Hideyoshi defeats the Hojo clan, crushing the last resistance to his control of the Japanese archipelago.
- John White finally manages to return to the Roanoke Colony in Virginia after three years and two unsuccessful attempts, but finds the colony completely deserted. The true fate of the colonists remains a mystery to this day.
- Sultan of Morocco Ahmad I al-Mansur dispatches an army of 4,000 men under the command of converted Spaniard Judar Pasha across the Sahara Desert to conquer the Songhai Empire in retaliation for not paying enough salt tribute. The Songhai meet the Moroccans at the Battle of Tondibi with a force of 40,000, but are easily defeated because they do not have any guns. The Moroccans continue their advance, sacking the Songhai cities of Timbuktu and Djenné and finally capturing the capital Gao, securing Moroccan hegemony over the Songhai, which would last until 1603.
- Forces loyal to Mughal emperor Akbar invade Sindh.
- The serpent, an early wooden precursor to the tuba, is invented in Auxerre, France by Edmé Guillaume.
- Spanish Jesuit missionary José de Acosta publishes his influential study of the new world, Historia Natural y Moral de las Indias ("Natural and Moral History of the Indies").
- Galileo publishes his book De motu gravium ("On the motion of heavy bodies").
- Christopher Marlowe writes his play The Jew of Malta.
- Sir Philip Sydney's pastoral romance Arcadia is published for the first time.
These people were born in 1590:
These people died in 1590:
- Charles, Cardinal de Bourbon, pretender to the French throne, hailed as king Charles X by the Catholic League, in captivity as a prisoner of the true king Henry IV.
- Pope Sixtus V, succeeded by Pope Urban VII.
- Pope Urban VII, succeeded by Pope Gregory XIV.
- Coptic pope Yoannis XIV, succeeded by Gabriel VIII.
- Orthodox Patriarch of Alexandria Silvester, succeeded by Meletius I.
- British spymaster Francis Walsingham.
- Japanese painter Kano Eitoku, founder of the influential Kano School of Japanese painting.
- Italian composer Lodovico Agostini.
- Italian scientist Giovanni Battista Benedetti.
- Irish chieftan Sorley Boy MacDonnell.
- French physician Ambroise Paré, an early pioneer of surgery.
1589 - 1590 - 1591